Work Hours and Health: Research Shows That Very Long Hours May Modestly Increase the Risk of Certain Health Outcomes
Fast Facts
The nation's workers have a variety of work schedules—and some work long hours by choice or necessity. But there have been concerns about how long work hours affect workers' health.
A 2022 law includes a provision for us to study trends in work hours. Among other things, we found that:
Average U.S. work hours have stayed at around 38 to 39 hours per week since 2003
Very long work hours—55 or more per week—may increase the risk of stroke and heart disease, but experts said more research is needed
We also analyzed working hours by age, gender, race and ethnicity, occupation, number of jobs, and other categories.
Highlights
What GAO Found
From 2003 to 2023, average work hours for U.S. workers remained relatively stable at an estimated 38 to 39 hours per week but increased for older workers, according to GAO's analysis of Current Population Survey (CPS) data.
- Age. Average weekly hours for older workers (ages 65+) increased by about 3 hours (from about 29 to 32 hours), while average weekly hours for prime-age workers (ages 25-54) remained relatively stable (at about 39 hours). In 2023, older workers comprised about 7 percent of the workforce.
- Gender. Men's average weekly work hours decreased by about 1 hour (from about 41 to 40 hours), while women's average weekly work hours increased by nearly 1 hour (from about 35 to 36 hours).
- Work schedule. The percentage of workers who usually worked standard full-time hours (35 to 40 hours per week) increased, while the percentages of workers who usually worked long hours (41 or more hours per week) or very long hours (55 or more hours per week) decreased.
GAO also found that on average from 2018 through 2023, compared to individuals who worked standard full-time hours, individuals who worked very long hours were more likely to be male, White (non-Hispanic), have at least a bachelor's degree, earn higher wages, and have multiple jobs, among other differences. Among individuals who worked very long hours, those with multiple jobs were more likely than those with one job to be female, Black (non-Hispanic) or Hispanic, and earn middle or low wages.
The reviews GAO identified found that working very long hours may modestly increase the risk of stroke and ischemic heart disease (coronary heart disease), relative to working standard full-time hours (see figure). While reviews found associations between long work hours and increased risks of type 2 diabetes, negative weight-related outcomes, and increased alcohol use, they did not draw conclusions about whether long work hours caused these increased risks. In addition, a review on long work hours and the risk of depression found no evidence of an association between the two. The experts GAO interviewed said more research is needed on the relationships between long work hours and poor health outcomes and behaviors. This includes whether there is a causal relationship between them, and how health risks may differ based on the type of work, working conditions, and other factors such as age and income level.
Research Results: Increased Risk of Stroke and Heart Disease Associated with Working 55 or More Hours Per Week, Relative to Working 35-40 Hours Per Week
Why GAO Did This Study
U.S. workers have a variety of work schedules. Some work long hours by choice or necessity. The Joint Explanatory Statement accompanying the Consolidated Appropriations Act, 2022 includes a provision for GAO to study trends in the work hours of U.S. workers. The Appropriations Committees expressed interest in understanding the relationship between long work hours and poor health outcomes.
This report addresses (1) how work hours for U.S. workers have changed over time, (2) how the characteristics of individuals who worked very long hours in recent years compare to those of standard full-time workers, and (3) research on the relationships between long work hours and health outcomes and behaviors.
GAO analyzed monthly data from the CPS, which is sponsored jointly by the U.S. Bureau of Labor Statistics and the U.S. Census Bureau, from 2003 through 2023. GAO analyzed data for employed workers ages 25 and over.
GAO also conducted a literature search for systematic reviews that synthesized the results of individual studies. GAO identified six reviews that examined the relationships between long work hours and health outcomes and behaviors that are common among U.S. adults (stroke, ischemic heart disease, type 2 diabetes, negative weight-related outcomes (weight gain, increase in body mass index, overweight, and obesity), alcohol use, and depression). All six reviews met GAO's methodological standards. GAO also interviewed the experts who authored four of the six reviews.
For more information, contact Thomas Costa at (202) 512-4769 or costat@gao.gov.